As disclosed in Patent Document 1, there is known an X-ray inspection apparatus including a fluorescent plate that converts X-rays emitted from an X-ray source and transmitted through a specimen into light and CCD cameras that capture images of the fluorescent plate. This apparatus uses a fluorescent plate constituted by a front-surface fluorescent plate located at an X-ray irradiation plane, a back-surface fluorescent plate located on the back side of the irradiation plane, and a metal filter located between them. The CCD cameras include a high-energy CCD camera and a low-energy CCD camera. The front-surface fluorescent plate and the back-surface fluorescent plate convert X-rays transmitted through a specimen into scintillation light. The two CCD cameras described above then perform image capturing.